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[2604:1380:4601:e00::3]) by mx.google.com with ESMTPS id v23-20020a056402185700b0055fd3109294si833579edy.659.2024.02.09.05.26.02 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Feb 2024 05:26:02 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-59359-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3; Authentication-Results: mx.google.com; arc=pass (i=1); spf=pass (google.com: domain of linux-kernel+bounces-59359-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) smtp.mailfrom="linux-kernel+bounces-59359-linux.lists.archive=gmail.com@vger.kernel.org" Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by am.mirrors.kernel.org (Postfix) with ESMTPS id 76BAE1F230C5 for ; Fri, 9 Feb 2024 13:26:02 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 93FEA381DD; Fri, 9 Feb 2024 13:25:58 +0000 (UTC) Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 16E65381AF; Fri, 9 Feb 2024 13:25:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707485158; cv=none; b=phMJBEegu2Ex9QtvMVDFGnCq0QSg4QT20haoFmeF5GGACvdfr4HwcjuhAqNJNBrkYXUXZvXuA2gSzesEXuB/+dZRZTPyXXh1qORGHrk4t7d5ELftXx1OmcJIKTIqvBED5qNZAJ90Y8t59/76c8E/A/0jlOBw2+teKtNxzZhNb28= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707485158; c=relaxed/simple; bh=tQUeUFmRa0OyLDyoC1Z9oHBdLuOcPOL6eT6C/1w5p44=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=g9w5hrcGGU0m7ClVHUMXiTIuTxjUCxmQYK9+7O5dcXh7Tx2jnGHjsSvodyY+u7ck1I17jux0HcM7SxXhOVTtFVJJE5FgVRd1e7Pau+LyAjwf2o9RKW6Ij4kpfQtugoWASad7nOKvKVx2fY8WVndy9Fx6Tj1zqdf2Et7e/6ehWD0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02B14C433F1; Fri, 9 Feb 2024 13:25:55 +0000 (UTC) Date: Fri, 9 Feb 2024 08:25:52 -0500 From: Steven Rostedt To: Vincent Donnefort Cc: mhiramat@kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, kernel-team@android.com Subject: Re: [PATCH v15 2/6] ring-buffer: Introducing ring-buffer mapping functions Message-ID: <20240209082552.1ab5c9b1@rorschach.local.home> In-Reply-To: <20240209102202.649049-3-vdonnefort@google.com> References: <20240209102202.649049-1-vdonnefort@google.com> <20240209102202.649049-3-vdonnefort@google.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 9 Feb 2024 10:21:58 +0000 Vincent Donnefort wrote: > +static void rb_update_meta_page(struct ring_buffer_per_cpu *cpu_buffer) > +{ > + struct trace_buffer_meta *meta = cpu_buffer->meta_page; > + > + WRITE_ONCE(meta->reader.read, cpu_buffer->reader_page->read); > + WRITE_ONCE(meta->reader.id, cpu_buffer->reader_page->id); > + WRITE_ONCE(meta->reader.lost_events, cpu_buffer->lost_events); > + > + WRITE_ONCE(meta->entries, local_read(&cpu_buffer->entries)); > + WRITE_ONCE(meta->overrun, local_read(&cpu_buffer->overrun)); > + WRITE_ONCE(meta->read, cpu_buffer->read); > + Small nit, but we should add a comment to the two flush_dache_folio() calls: /* Some archs do not have data cache coherency between kernel and user space */ > + flush_dcache_folio(virt_to_folio(cpu_buffer->meta_page)); > +} > + -- Steve